Add copy output translation key

This serves as an addition to the previous commits. It is the result of
running `yarn i18n:generate` on the state after adding the copy output
button to the serial monitor (see 2df3f46). I hope that this will
resolve the current Github action failure.

Author: 502E532E

i18n/en.json

@@ -435,6 +435,7 @@
       "autoscroll": "Autoscroll",
       "carriageReturn": "Carriage Return",
       "connecting": "Connecting to '{0}' on '{1}'...",
+      "copyOutput": "Copy Output",
       "message": "Message (Enter to send message to '{0}' on '{1}')",
       "newLine": "New Line",
       "newLineCarriageReturn": "Both NL & CR",